What does "Couldn't initialize streams, probably unsupported codec combination" mean?
The error means that Blender can't read or write to a specific codec. Speculation based on the screen shot:

your on windows, and probably don't have Ogg/Vorbis codecs installed on your system. You can download the OpenCodecs package, which will allow you to play ogg/ogv (vorbis/theora) on windows. 

It's generally included in Linux/osx, so your probably getting examples from someone who works in one of those systems.

Or you could try setting the output of your render to a codec you probably already have like Mpeg, h.264, or Windows Media?